down2 - down sampling by factor of 2
This function down samples the input vector by factor of 2. The output length would be half length of the input vector. Odd-indexed element would be abandoned and even-indexed element would be retained. If the length of the input vector And the input could be row vectors or column vectors. The output vector would be row vectors.
-->a=[1 2 3 4 5]; -->b=down2(a) ans = 2 4 -->a=a'; -->b=down2(a) ans = 2 4 -->a=[1 2 3;4 5 6]; -->b=down2(a) Input should be vectors rather than matrixes! -->a=1; -->b=down2(a) Input should be vectors!